A decarbonized vinyl chloride synthesis via selective oxidative coupling of methyl chloride

Selective coupling of C1 platform molecules to C2 olefins is a cornerstone for establishing a sustainable chemical industry based on non petroleum sources. Vinyl chloride (C2H3Cl), one of top commodity petrochemicals, is commercially produced from coal or oil derived C2 hydrocarbon (acetylene and ethylene) feedstocks with a high carbon footprint. Here, we report a decarbonized vinyl chloride synthesis via selective oxidative coupling of methyl chloride. This is enabled by a solid catalyst, featuring tungstate sub nanoclusters embedded in a zirconia matrix, which effectively captures CH2Cl radicals homogeneously generated in CH3Cl oxy pyrolysis and selectively couples them into C2H3Cl. In situ synchrotron based vacuum ultraviolet photoionization mass spectrometry provides direct experimental evidence of the homogeneous heterogeneous reaction mechanism. The process achieves methyl chloride conversion of 10 – 65% with a high vinyl chloride selectivity (60 – 75%) at a reaction temperature (600 – 750 °C), which is much lower than the traditional pyrolysis (> 850 °C). It also delivers a stable performance (at a vinyl chloride yield of ca. 30%) with no deactivation observed during a 50 hour test. Furthermore, combining with reaction of methanol and HCl to produce methyl chloride, we establish a methanol to vinyl chloride (MTV) route with the potential for significant reductions in climate change impact (24%) and cost (38%) compared to the state of the art ethylene based balanced process. A more remarkable 237% reduction in climate change impacts can be anticipated in the future oriented green scenario for MTV process primarily attributed to the utilization of renewable C1 feedstocks that results in negative net contributions to the overall impacts.